It just so happens that on this particular board, our physical SDRAM starts at 256MB.
54
Out of necessity (space), this is a very simplified description of the sequence of events. The actual mechanism is similar in concept, but several significant details are omitted for clarity. You are encouraged to consult the kernel source code for more details. See .../init/main.c and .../init/do_mounts*.c.
55
do_basic_setup is called from .../init/main.c and calls do_initcalls(). This causes driver module initialization routines to be called. This was described in detail in Chapter 5 and shown in Listing 5-10 .
56
Some embedded designs protect the bootloader and provide callbacks to bootloader routines, but this is almost never a good design approach. Linux is far more capable than bootloaders, so there is often little point in doing so.
57
The details differ, depending upon architecture, processor, and details of the hardware design.
58
This data was taken directly from the 405GP user's manual, referenced at the end of this chapter.
59
This is mostly for historical reasons. From the early days of PCs, BIOS programs loaded only the first sector of a disk drive and passed control to it.
60
In an acknowledgment of the number of bootloaders in existence, the YAMON user's guide bills itself as Yet Another MONitor.
61
The terms module and device driver are used here interchangeably.
62
This path is used by Red Hat and Fedora distributions, and is also required by the File System Hierarchy Standard referenced at the end of this chapter. Other distributions might use different locations in the file system for kernel modules.
63
Hosting a target board and NFS root mount are covered in detail in Chapter 12, 'Embedded Development Environment'.
64
If you don't see the messages on the console, either disable your syslogd logger or lower the console loglevel. We describe how to do this in Chapter 14, 'Kernel Debugging Techniques'.
65
/proc/modules is part of the proc file system, which is introduced in Chapter 9, 'File Systems'.
66
Reference to this standard is found in the ' Suggestions for Additional Reading,' at the end of this chapter.
67
Actually, the open() call is a C library wrapper function around the Linux sys_open() system call.
